const _ = require('lodash');
const fp = require('lodash/fp')

const cars = [
    { name: 'Ferrari FF', horsepower: 660, dollar_value: 700000, in_stock: true},
    { name: 'Spyker C12 Zagato', horsepower: 650, dollar_value: 648000, in_stock: false},
    { name: 'Jaguar SKR-S', horsepower: 550, dollar_value: 132000, in_stock: false},
    { name: 'Audi R8', horsepower: 525, dollar_value: 114200, in_stock: false},
    { name: 'Aston Martin One-77', horsepower: 750, dollar_value: 1850000, in_stock: true},
    { name: 'Pagani Huayra', horsepower: 700, dollar_value: 1300000, in_stock: false},
];

// 1
let isLastInStock = fp.flowRight(fp.prop('in_stock'), fp.last);
console.log(isLastInStock(cars));

// 2
let firstCarName = fp.flowRight( fp.prop('name'), fp.first);
console.log(firstCarName(cars));


// 3
let _average = function (xs) {
    return fp.reduce(fp.add, 0, xs) / xs.length
}

let averageDollarValue = fp.flowRight(_average, fp.map(v => v.dollar_value))
console.log(averageDollarValue(cars));

// 4
let _underscore = fp.replace(/\W+/g, '_')
let lowerCase = (str) => str.toLowerCase()
let sanitizeNames = fp.map(fp.flowRight(lowerCase, _underscore, fp.prop('name')))
console.log(sanitizeNames(cars))
